package com.atguigu.gulimall.gulimallproduct.service.impl;

import org.springframework.stereotype.Service;

import java.util.List;
import java.util.Map;
import java.util.stream.Collectors;

import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.baomidou.mybatisplus.core.metadata.IPage;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.atguigu.common.utils.PageUtils;
import com.atguigu.common.utils.Query;

import com.atguigu.gulimall.gulimallproduct.dao.CategoryDao;
import com.atguigu.gulimall.gulimallproduct.entity.CategoryEntity;
import com.atguigu.gulimall.gulimallproduct.service.CategoryService;


@Service("categoryService")
public class CategoryServiceImpl extends ServiceImpl<CategoryDao, CategoryEntity> implements CategoryService {

    @Override
    public PageUtils queryPage(Map<String, Object> params) {
        IPage<CategoryEntity> page = this.page(
                new Query<CategoryEntity>().getPage(params),
                new QueryWrapper<CategoryEntity>()
        );

        return new PageUtils(page);
    }

    /**
     * 三级分类实现：
     *      1、List集合使用stream()api操作,流式计算+递归
     *      2、List.stream().filter(fun).map(fun).sort(fun).collect(Collectors.toList())
     * @return
     */
    @Override
    public List<CategoryEntity> listWithTree() {
        //1、查出所有分类
        List<CategoryEntity> entities = baseMapper.selectList(null);
        //2、组装层父子的树状结构
            //1.找到所有的一级分类
        List<CategoryEntity> level1Menus = entities.stream().filter(categoryEntity ->
             categoryEntity.getParentCid() == 0
        ).map((menu)->{
            menu.setChildren(getChilds(menu,entities));
            return menu;
        }).sorted((menu1,menu2)->{
            return (menu1.getSort()==null?0:menu1.getSort())-(menu2.getSort()==null?0:menu2.getSort());
        }).collect(Collectors.toList());

        return level1Menus;
    }
    //递归查找所有菜单的子菜单
    private List<CategoryEntity> getChilds(CategoryEntity root, List<CategoryEntity> all){
        List<CategoryEntity> child = all.stream().filter(categoryEntity ->
                categoryEntity.getParentCid() == root.getCatId()).map((menu)->{
//                    找到子菜单
                    menu.setChildren(getChilds(menu,all));
                    return menu;
        }).sorted((menu1,menu2)->{
//            菜单的排序
            return (menu1.getSort()==null?0:menu1.getSort())-(menu2.getSort()==null?0:menu2.getSort());
        }).collect(Collectors.toList());
        return child;
    }

    @Override
    public void removeMenuByIds(List<Long> longs) {
        //TODO 1、检查当前删除的菜单，是否被其他地方引用
        baseMapper.deleteBatchIds(longs);
    }
}